The Asplenic Patient: Post-Insult Immunocompetence, Infection, and Vaccination

Background: Splenic injury can occur through multiple mechanisms and may result in various degrees of residual immunocompetence. Functionally or anatomically asplenic patients are at higher risk for infection, particularly with encapsulated bacteria. Vaccination is recommended to prevent infection with these organisms; however, the recommendations are routinely updated, and vaccine selection and timing are complex. Methods: Review of the pertinent English-language literature, including the recommendations of the U.S. Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices. Results: Overwhelming post-splenectomy infection is associated with high morbidity and mortality rates. Patients requiring splenectomy for trauma-related injury appear to be at lower risk for infection than those undergoing splenectomy for a hematologic or oncologic indication. Initial vaccination is dependent on immunization history but generally should consist of the 13-valent pneumococcal conjugate, quadrivalent meningococcal conjugate, meningococcal serogroup B, and Haemophilus influenzae serotype b (Hib) vaccines. Antimicrobial prophylaxis for certain asplenic patients, such as children under the age of five y, may be indicated. Conclusion: Immunization remains a key measure to prevent overwhelming post-splenectomy infection. Consideration of new recommendations and indications, possible interactions, and timing remains important to including optimal response to the vaccines.